一个非常简单的解决方案是创建 URLComponents，分配查询部分并将查询项(平面)映射到它们的值>

let string = "user_one_id=7&user_two_id=5"let components = URLComponents(string: "http://dummy.com?" + string)让 userIDs = components?.queryItems?.flatMap{ $0.value }打印(用户 ID)

let string = "user_one_id=7&user_two_id=5"var 组件 = URLComponents()components.query = 字符串让 userIDs = components.queryItems!.flatMap{ $0.value }打印(用户 ID)

I want to get a substring from a larger string in swift 3. The string is just the query part of a url:

user_one_id=7&user_two_id=5

I just want the id of each user, so I want 7 and 5.

A quite simple solution is to create URLComponents, assign the query part and (flat)map the query items to their values

let string = "user_one_id=7&user_two_id=5" let components = URLComponents(string: "http://dummy.com?" + string) let userIDs = components?.queryItems?.flatMap{ $0.value } print(userIDs)

let string = "user_one_id=7&user_two_id=5"
var components = URLComponents()
components.query = string
let userIDs = components.queryItems!.flatMap{ $0.value }
print(userIDs)